PCOS & assisted fertility

Aimee
Hi!
I am currently trying for baby number 2. Baby 1 I conceived naturally after a laparoscopy to remove endometriosis. 
This time around every thing seems to be a lot more difficult. I have completed two unsuccessful rounds of clomid with lots of side effects. Terrible migraines & vomitting 5 days after each round. 
My doctor suggested we try one more round with metformin which is concerning me because I am worried the additional metformin will worsen my side effects I'm already having with clomid. 
She also suggested letrozol which is unapproved in Australia and I don't think I'm comfortable with that. I've read there have been studies which increase the risk of birth defects. 
The last option she presented was HSF injections but seeing as I am young and have PCOS she is concerned about high risk of multiples (3 or more!)
I'm so confused and overwhelmed. It's completely consuming me at the moment. I feel nervous to take more clomid after having a terrible time the last 2 times. Any advice, stories would help. I got back to the doctor in a few days to proceed with one of the above paths. 
Thanks for reading xxx